1
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Lokki AI, Ren Z, Triebwasser M, Daly E, Perola M, Auro K, Burwick R, Salmon JE, Daly M, Laivuori H, Atkinson JP, Java A, Meri S. Identification of complement factor H variants that predispose to pre-eclampsia: A genetic and functional study. BJOG 2023; 130:1473-1482. [PMID: 37156755 PMCID: PMC10592561 DOI: 10.1111/1471-0528.17529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 04/18/2023] [Accepted: 04/24/2023] [Indexed: 05/10/2023]
Abstract
OBJECTIVE The objective of the study was to investigate the role of genetic variants in complement proteins in pre-eclampsia. DESIGN In a case-control study involving 609 cases and 2092 controls, five rare variants in complement factor H (CFH) were identified in women with severe and complicated pre-eclampsia. No variants were identified in controls. SETTING Pre-eclampsia is a leading cause of maternal and fetal morbidity and mortality. Immune maladaptation, in particular, complement activation that disrupts maternal-fetal tolerance leading to placental dysfunction and endothelial injury, has been proposed as a pathogenetic mechanism, but this remains unproven. POPULATION We genotyped 609 pre-eclampsia cases and 2092 controls from FINNPEC and the national FINRISK cohorts. METHODS Complement-based functional and structural assays were conducted in vitro to define the significance of these five missense variants and each compared with wild type. MAIN OUTCOME MEASURES Secretion, expression and ability to regulate complement activation were assessed for factor H proteins harbouring the mutations. RESULTS We identified five heterozygous rare variants in complement factor H (L3V, R127H, R166Q, C1077S and N1176K) in seven women with severe pre-eclampsia. These variants were not identified in controls. Variants C1077S and N1176K were novel. Antigenic, functional and structural analyses established that four (R127H, R166Q, C1077S and N1176K) were deleterious. Variants R127H and C1077S were synthesised, but not secreted. Variants R166Q and N1176K were secreted normally but showed reduced binding to C3b and consequently defective complement regulatory activity. No defect was identified for L3V. CONCLUSIONS These results suggest that complement dysregulation due to mutations in complement factor H is among the pathophysiological mechanisms underlying severe pre-eclampsia.
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Affiliation(s)
- A Inkeri Lokki
- Immunobiology Research Program, Bacteriology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Heart and Lung Centre, Helsinki University Hospital, Helsinki, Finland
| | - Zhen Ren
- Division of Clinical Immunology and Allergy, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Michael Triebwasser
- Division of Pediatric Hematology and Oncology, Department of Pediatrics, University of Michigan, Ann Arbor, Michigan, USA
| | - Emma Daly
- Hospital and Harvard Medical School, Boston, Massachusetts, USA
| | - Markus Perola
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
| | - Kirsi Auro
- Department of Health, National Institute for Health and Welfare, Helsinki, Finland
| | - Richard Burwick
- Maternal Fetal Medicine, San Gabriel Valley Perinatal Medical Group, Pomona Valley Hospital Medical Center, Pomona, California, USA
- Department of Obstetrics and Gynecology, Cedars-Sinai Medical Center, Los Angeles, California, USA
| | - Jane E Salmon
- Hospital for Special Surgery, Weill Medical College of Cornell University, New York, New York, USA
| | - Mark Daly
- Analytic and Translational Genetics Unit, Massachusetts General Hospital, Boston, Massachusetts, USA
- Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
| | - Hannele Laivuori
- Medical and Clinical Genetics, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- Institute for Molecular Medicine Finland, Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland
- Department of Obstetrics and Gynaecology, Tampere University Hospital, Tampere University, Tampere, Finland
- Centre for Child, Adolescent, and Maternal Health Research, Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - John P Atkinson
- Division of Rheumatology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Anuja Java
- Division of Nephrology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Seppo Meri
- Immunobiology Research Program, Bacteriology and Immunology, University of Helsinki and Helsinki University Hospital, Helsinki, Finland
- HUSLAB Diagnostic Centre, Helsinki University Hospital, Helsinki, Finland
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2
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Ruiz-Molina N, Parsons J, Decker EL, Reski R. Structural modelling of human complement FHR1 and two of its synthetic derivatives provides insight into their in-vivo functions. Comput Struct Biotechnol J 2023; 21:1473-1486. [PMID: 36851916 PMCID: PMC9957715 DOI: 10.1016/j.csbj.2023.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 02/05/2023] Open
Abstract
Human complement is the first line of defence against invading pathogens and is involved in tissue homeostasis. Complement-targeted therapies to treat several diseases caused by a dysregulated complement are highly desirable. Despite huge efforts invested in their development, only very few are currently available, and a deeper understanding of the numerous interactions and complement regulation mechanisms is indispensable. Two important complement regulators are human Factor H (FH) and Factor H-related protein 1 (FHR1). MFHR1 and MFHR13, two promising therapeutic candidates based on these regulators, combine the dimerization and C5-regulatory domains of FHR1 with the central C3-regulatory and cell surface-recognition domains of FH. Here, we used AlphaFold2 to model the structure of these two synthetic regulators. Moreover, we used AlphaFold-Multimer (AFM) to study possible interactions of C3 fragments and membrane attack complex (MAC) components C5, C7 and C9 in complex with FHR1, MFHR1, MFHR13 as well as the best-known MAC regulators vitronectin (Vn), clusterin and CD59, whose experimental structures remain undetermined. AFM successfully predicted the binding interfaces of FHR1 and the synthetic regulators with C3 fragments and suggested binding to C3. The models revealed structural differences in binding to these ligands through different interfaces. Additionally, AFM predictions of Vn, clusterin or CD59 with C7 or C9 agreed with previously published experimental results. Because the role of FHR1 as MAC regulator has been controversial, we analysed possible interactions with C5, C7 and C9. AFM predicted interactions of FHR1 with proteins of the terminal complement complex (TCC) as indicated by experimental observations, and located the interfaces in FHR11-2 and FHR14-5. According to AFM prediction, FHR1 might partially block the C3b binding site in C5, inhibiting C5 activation, and block C5b-7 complex formation and C9 polymerization, with similar mechanisms of action as clusterin and vitronectin. Here, we generate hypotheses and give the basis for the design of rational approaches to understand the molecular mechanism of MAC inhibition, which will facilitate the development of further complement therapeutics.
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Affiliation(s)
- Natalia Ruiz-Molina
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Juliana Parsons
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Eva L Decker
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Ralf Reski
- Plant Biotechnology, Faculty of Biology, University of Freiburg, Freiburg, Germany.,Signalling Research Centres BIOSS and CIBSS, University of Freiburg, Freiburg, Germany
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3
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Rodríguez de Córdoba S. Genetic variability shapes the alternative pathway complement activity and predisposition to complement-related diseases. Immunol Rev 2023; 313:71-90. [PMID: 36089777 PMCID: PMC10086816 DOI: 10.1111/imr.13131] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The implementation of next-generation sequencing technologies has provided a sharp picture of the genetic variability in the components and regulators of the alternative pathway (AP) of the complement system and has revealed the association of many AP variants with different rare and common diseases. An important finding that has emerged from these analyses is that each of these complement-related diseases associate with genetic variants altering specific aspects of the activation and regulation of the AP. These genotype-phenotype correlations have provided valuable insights into their pathogenic mechanisms with important diagnostic and therapeutic implications. While genetic variants in coding regions and structural variants are reasonably well characterized and occasionally have been instrumental to uncover unknown features of the complement proteins, data about complement expressed quantitative trait loci are still very limited. A crucial task for future studies will be to identify these quantitative variations and to determine their impact in the overall activity of the AP. This is fundamental as it is now clear that the consequences of genetic variants in the AP are additive and that susceptibility or resistance to disease is the result of specific combinations of genetic variants in different complement components and regulators ("complotypes").
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4
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Yokoo T, Tanabe A, Yoshida Y, Caaveiro JMM, Nakakido M, Ikeda Y, Fujimura Y, Matsumoto M, Entzminger K, Maruyama T, Okumura CJ, Nangaku M, Tsumoto K. Antibody recognition of complement Factor H reveals a flexible loop involved in Atypical Hemolytic Uremic Syndrome pathogenesis. J Biol Chem 2022; 298:101962. [PMID: 35452676 PMCID: PMC9127587 DOI: 10.1016/j.jbc.2022.101962] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2022] [Revised: 04/15/2022] [Accepted: 04/16/2022] [Indexed: 11/28/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a disease associated with dysregulation of the immune complement system, especially of the alternative pathway (AP). Complement factor H (CFH), consisting of 20 domains called CCP1-20, downregulates the AP as a cofactor for mediating C3 inactivation by complement factor I (CFI). However, anomalies related to CFH are known to cause excessive complement activation and cytotoxicity. In aHUS, mutations and the presence of anti-CFH autoantibodies (AAbs) have been reported as plausible causes of CFH dysfunction, and it is known that CFH-related aHUS carries a high probability of end-stage renal disease. Elucidating the detailed functions of CFH at the molecular level will help to understand aHUS pathogenesis. Herein, we used biophysical data to reveal that a heavy-chain antibody fragment, termed VHH4, recognized CFH with high affinity. Hemolytic assays also indicated that VHH4 disrupted the protective function of CFH on sheep erythrocytes. Furthermore, X-ray crystallography revealed that VHH4 recognized the Leu1181-Leu1189CCP20 loop, a known anti-CFH AAbs epitope. We next analyzed the dynamics of the C-terminal region of CFH, and showed that the epitopes recognized by anti-CFH AAbs and VHH4 were the most flexible regions in CCP18-20. Finally, we conducted mutation analyses to elucidate the mechanism of VHH4 recognition of CFH, and revealed that VHH4 inserts Trp1183CCP20 residue of CFH into the pocket formed by the complementary determining region 3 loop. These results suggested that anti-CFH AAbs may adopt a similar molecular mechanism to recognize the flexible loop of Leu1181-Leu1189CCP20, leading to aHUS pathogenesis.
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Affiliation(s)
- Takanori Yokoo
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
| | - Aki Tanabe
- Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoko Yoshida
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Jose M M Caaveiro
- Department of Global Healthcare, Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1, Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan
| | - Makoto Nakakido
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.
| | - Yoichiro Ikeda
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Yoshihiro Fujimura
- Department of Blood Transfusion Medicine, Nara Medical University, 840, Shijo-Cho, Kashihara, Nara, 634-8521, Japan
| | - Masanori Matsumoto
- Department of Blood Transfusion Medicine, Nara Medical University, 840, Shijo-Cho, Kashihara, Nara, 634-8521, Japan
| | - Kevin Entzminger
- Abwiz Bio Inc, 9823 Pacific Heights Blvd, Ste J, San Diego, California, 92121, USA
| | - Toshiaki Maruyama
- Abwiz Bio Inc, 9823 Pacific Heights Blvd, Ste J, San Diego, California, 92121, USA
| | - C J Okumura
- Abwiz Bio Inc, 9823 Pacific Heights Blvd, Ste J, San Diego, California, 92121, USA
| | - Masaomi Nangaku
- Division of Nephrology and Endocrinology, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan
| | - Kouhei Tsumoto
- Department of Chemistry and Biotechnology, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo 113-8656, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, 7-3-1, Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan; The institute of Medical Science, The University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo, 108-8639, Japan.
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5
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Anliker M, Drees D, Loacker L, Hafner S, Griesmacher A, Hoermann G, Fux V, Schennach H, Hörtnagl P, Dopler A, Schmidt S, Bellmann-Weiler R, Weiss G, Marx-Hofmann A, Körper S, Höchsmann B, Schrezenmeier H, Schmidt CQ. Upregulation of Checkpoint Ligand Programmed Death-Ligand 1 in Patients with Paroxysmal Nocturnal Hemoglobinuria Explained by Proximal Complement Activation. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2022; 208:1248-1258. [PMID: 35173033 DOI: 10.4049/jimmunol.2100031] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 12/17/2021] [Indexed: 12/12/2022]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare hemolytic disease driven by impaired complement regulation. Mutations in genes encoding the enzymes that build the GPI anchors are causative, with somatic mutations in the PIG-A gene occurring most frequently. As a result, the important membrane-bound complement regulators CD55 and CD59 are missing on the affected hematopoietic stem cells and their progeny, rendering those cells vulnerable to complement attack. Immune escape mechanisms sparing affected PNH stem cells from removal are suspected in the PNH pathogenesis, but molecular mechanisms have not been elucidated. We hypothesized that exuberant complement activity in PNH results in enhanced immune checkpoint interactions, providing a molecular basis for the potential immune escape in PNH. In a series of PNH patients, we found increased expression levels of the checkpoint ligand programmed death-ligand 1 (PD-L1) on granulocytes and monocytes, as well as in the plasma of PNH patients. Mechanistically, we demonstrate that complement activation leading to the decoration of particles/cells with C3- and/or C4-opsonins increased PD-L1 expression on neutrophils and monocytes as shown for different in vitro models of classical or alternative pathway activation. We further establish in vitro that complement inhibition at the level of C3, but not C5, inhibits the alternative pathway-mediated upregulation of PD-L1 and show by means of soluble PD-L1 that this observation translates into the clinical situation when PNH patients are treated with either C3 or C5 inhibitors. Together, the presented data show that the checkpoint ligand PD-L1 is increased in PNH patients, which correlates with proximal complement activation.
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Affiliation(s)
- Markus Anliker
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Daniela Drees
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Lorin Loacker
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Susanne Hafner
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Andrea Griesmacher
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Gregor Hoermann
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria.,MLL Munich Leukemia Laboratory, Munich, Germany
| | - Vilmos Fux
- Central Institute for Medical and Chemical Laboratory Diagnosis, University Hospital, Innsbruck, Austria
| | - Harald Schennach
- Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, Innsbruck, Austria
| | - Paul Hörtnagl
- Central Institute of Blood Transfusion and Immunology, University Hospital Innsbruck, Innsbruck, Austria
| | - Arthur Dopler
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Stefan Schmidt
- Department of Internal Medicine V, Medical University of Innsbruck, Innsbruck, Austria; and
| | - Rosa Bellmann-Weiler
- Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Austria
| | - Günter Weiss
- Department of Internal Medicine II, Innsbruck Medical University, Innsbruck, Austria
| | - Astrid Marx-Hofmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Sixten Körper
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany.,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany; .,Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service, Baden-Württemberg-Hessen and University Hospital of Ulm, Ulm, Germany
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany;
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6
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Xu B, Kang Y, Du Y, Guo W, Zhu L, Zhang H. Atypical Hemolytic Uremic Syndrome-Associated FHR1 Isoform FHR1*B Enhances Complement Activation and Inflammation. Front Immunol 2022; 13:755694. [PMID: 35126388 PMCID: PMC8814109 DOI: 10.3389/fimmu.2022.755694] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Accepted: 01/03/2022] [Indexed: 11/13/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a rare but severe type of thrombotic microangiopathy that is triggered by the abnormal activation of the alternative complement pathway. Previous studies have reported that three completely linked coding variants of CFHR1 form two haplotypes, namely, CFHR1*A (c.469C, c.475C, c.523G) and CFHR1*B (c.469T, c.475G, c.523C). CFHR1*B is associated with susceptibility to aHUS. To explore the genetic mechanism by which CFHR1 isoforms contribute to aHUS, we compared the structures of FHR1*A and FHR1*B by homology modeling and found differences in the angles between SCR3 and SCR4-SCR5, as FHR1*B had a larger angle than FHR1*A. Then, we expressed FHR1*A and FHR1*B recombinant proteins and compared their functions in complement system regulation and inflammation. We found that FHR1*B presented a significantly higher capacity for binding C3b and necrotic cells than FHR1*A. In a cofactor assay, the FHR-1*B showed stronger influence on FH mediated cofactor function than the FHR-1*A, resulted in fewer C3b cleavage products. In the C3 convertase assays, FHR1*B showed more powerful effect compared with FHR1*A regarding to de-regulate FH function of inhibition the assembling of C3bBb. Additionally, we also found that FHR1*B triggered monocytes to secrete higher levels of IL-1β and IL-6 than FHR1*A. In the present study, we showed that variants of CFHR1 might differently affect complement activation and sterile inflammation. Our findings provide a possible mechanism underlying the predisposition to aHUS caused by CFHR1 isoform CFHR1*B.
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Affiliation(s)
- Boyang Xu
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease (Peking University), National Health Commission, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China
| | - Yuqi Kang
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease (Peking University), National Health Commission, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China
| | - Yujing Du
- Department of Nuclear Medicine, Peking University First Hospital, Beijing, China
| | - Weiyi Guo
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease (Peking University), National Health Commission, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China
| | - Li Zhu
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease (Peking University), National Health Commission, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China
| | - Hong Zhang
- Renal Division, Department of Medicine, Peking University First Hospital, Peking University Institute of Nephrology, Key Laboratory of Renal Disease (Peking University), National Health Commission, Key Laboratory of Chronic Kidney Disease Prevention and Treatment, Ministry of Education, Beijing, China
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7
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Dunne OM, Gao X, Nan R, Gor J, Adamson PJ, Gordon DL, Moulin M, Haertlein M, Forsyth VT, Perkins SJ. A Dimerization Site at SCR-17/18 in Factor H Clarifies a New Mechanism for Complement Regulatory Control. Front Immunol 2021; 11:601895. [PMID: 33552059 PMCID: PMC7859452 DOI: 10.3389/fimmu.2020.601895] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 12/03/2020] [Indexed: 11/15/2022] Open
Abstract
Complement Factor H (CFH), with 20 short complement regulator (SCR) domains, regulates the alternative pathway of complement in part through the interaction of its C-terminal SCR-19 and SCR-20 domains with host cell-bound C3b and anionic oligosaccharides. In solution, CFH forms small amounts of oligomers, with one of its self-association sites being in the SCR-16/20 domains. In order to correlate CFH function with dimer formation and the occurrence of rare disease-associated variants in SCR-16/20, we identified the dimerization site in SCR-16/20. For this, we expressed, in Pichia pastoris, the five domains in SCR-16/20 and six fragments of this with one-three domains (SCR-19/20, SCR-18/20, SCR-17/18, SCR-16/18, SCR-17 and SCR-18). Size-exclusion chromatography suggested that SCR dimer formation occurred in several fragments. Dimer formation was clarified using analytical ultracentrifugation, where quantitative c(s) size distribution analyses showed that SCR-19/20 was monomeric, SCR-18/20 was slightly dimeric, SCR-16/20, SCR-16/18 and SCR-18 showed more dimer formation, and SCR-17 and SCR-17/18 were primarily dimeric with dissociation constants of ~5 µM. The combination of these results located the SCR-16/20 dimerization site at SCR-17 and SCR-18. X-ray solution scattering experiments and molecular modelling fits confirmed the dimer site to be at SCR-17/18, this dimer being a side-by-side association of the two domains. We propose that the self-association of CFH at SCR-17/18 enables higher concentrations of CFH to be achieved when SCR-19/20 are bound to host cell surfaces in order to protect these better during inflammation. Dimer formation at SCR-17/18 clarified the association of genetic variants throughout SCR-16/20 with renal disease.
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Affiliation(s)
- Orla M Dunne
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom.,Life Sciences Group, Institut Laue Langevin, Grenoble, France
| | - Xin Gao
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom.,Division of Medicine, University College London, London, United Kingdom
| | - Ruodan Nan
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Jayesh Gor
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
| | - Penelope J Adamson
- Department of Microbiology and Infectious Diseases, Flinders Medical Centre and Flinders University, Bedford Park, SA, Australia
| | - David L Gordon
- Department of Microbiology and Infectious Diseases, Flinders Medical Centre and Flinders University, Bedford Park, SA, Australia
| | - Martine Moulin
- Life Sciences Group, Institut Laue Langevin, Grenoble, France
| | | | - V Trevor Forsyth
- Life Sciences Group, Institut Laue Langevin, Grenoble, France.,Faculty of Natural Sciences, Keele University, Staffordshire, United Kingdom
| | - Stephen J Perkins
- Division of Biosciences, Department of Structural and Molecular Biology, University College London, London, United Kingdom
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8
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Skerka C, Pradel G, Halder LD, Zipfel PF, Zipfel SLH, Strauß O. Factor H-related protein 1: a complement regulatory protein and guardian of necrotic-type surfaces. Br J Pharmacol 2020; 178:2823-2831. [PMID: 33085794 DOI: 10.1111/bph.15290] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 09/21/2020] [Accepted: 10/01/2020] [Indexed: 11/30/2022] Open
Abstract
Factor H-related protein 1 (FHR-1) is a member of the factor H protein family, which is involved in regulating innate immune complement reactions. Genetic modification of the encoding gene, CFHR1 on human chromosome 1, is involved in diseases such as age-related macular degeneration, C3 glomerulopathy and atypical haemolytic uraemic syndrome, indicating an important role for FHR-1 in human health. Recent research data demonstrate that FHR-1 levels increase in IgA nephropathy and anti-neutrophilic cytoplasmic autoantibodies (ANCA) vasculitis and that FHR-1 induces strong inflammation in monocytes on necrotic-type surfaces, suggesting a complement-independent role. These new results increase our knowledge about the role of this complement protein in pathology and provide a new therapeutic target, particularly in the context of inflammatory diseases induced by necrosis. This review summarizes current knowledge about FHR-1 and discusses its role in complement reactions and inflammation. LINKED ARTICLES: This article is part of a themed issue on Canonical and non-canonical functions of the complement system in health and disease. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.14/issuetoc.
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Affiliation(s)
- Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Gabriele Pradel
- Division of Cellular and Applied Infection Biology, RWTH Aachen University, Aachen, Germany
| | - Luke D Halder
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Hans-Knöll-Institute, Jena, Germany
| | - Svante L H Zipfel
- Department of Cardiovascular Surgery, University Heart Center, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Olaf Strauß
- Experimental Ophthalmology, Charité University Medicine, Campus Virchow Clinic, Berlin, Germany
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9
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Potentiation of complement regulator factor H protects human endothelial cells from complement attack in aHUS sera. Blood Adv 2020; 3:621-632. [PMID: 30804016 DOI: 10.1182/bloodadvances.2018025692] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 01/24/2019] [Indexed: 12/12/2022] Open
Abstract
Mutations in the gene encoding for complement regulator factor H (FH) severely disrupt its normal function to protect human cells from unwanted complement activation, resulting in diseases such as atypical hemolytic uremic syndrome (aHUS). aHUS presents with severe hemolytic anemia, thrombocytopenia, and renal disease, leading to end-stage renal failure. Treatment of severe complement-mediated disease, such as aHUS, by inhibiting the terminal complement pathway, has proven to be successful but at the same time fails to preserve the protective role of complement against pathogens. To improve complement regulation on human cells without interfering with antimicrobial activity, we identified an anti-FH monoclonal antibody (mAb) that induced increased FH-mediated protection of primary human endothelial cells from complement, while preserving the complement-mediated killing of bacteria. Moreover, this FH-activating mAb restored complement regulation in sera from aHUS patients carrying various heterozygous mutations in FH known to impair FH function and dysregulate complement activation. Our data suggest that FH normally circulates in a less active conformation and can become more active, allowing enhanced complement regulation on human cells. Antibody-mediated potentiation of FH may serve as a highly effective approach to inhibit unwanted complement activation on human cells in a wide range of hematological diseases while preserving the protective role of complement against pathogens.
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Makou E, Bailey RG, Johnston H, Parkin JD, Hulme AN, Hähner G, Barlow PN. Combining SPR with atomic-force microscopy enables single-molecule insights into activation and suppression of the complement cascade. J Biol Chem 2019; 294:20148-20163. [PMID: 31719147 PMCID: PMC6937562 DOI: 10.1074/jbc.ra119.010913] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2019] [Revised: 11/07/2019] [Indexed: 12/05/2022] Open
Abstract
Activation and suppression of the complement system compete on every serum-exposed surface, host or foreign. Potentially harmful outcomes of this competition depend on surface molecules through mechanisms that remain incompletely understood. Combining surface plasmon resonance (SPR) with atomic force microscopy (AFM), here we studied two complement system proteins at the single-molecule level: C3b, the proteolytically activated form of C3, and factor H (FH), the surface-sensing C3b-binding complement regulator. We used SPR to monitor complement initiation occurring through a positive-feedback loop wherein surface-deposited C3b participates in convertases that cleave C3, thereby depositing more C3b. Over multiple cycles of flowing factor B, factor D, and C3 over the SPR chip, we amplified C3b from ∼20 to ∼220 molecules·μm−2. AFM revealed C3b clusters of up to 20 molecules and solitary C3b molecules deposited up to 200 nm away from the clusters. A force of 0.17 ± 0.02 nanonewtons was needed to pull a single FH molecule, anchored to the AFM probe, from its complex with surface-attached C3b. The extent to which FH molecules stretched before detachment varied widely among complexes. Performing force-distance measurements with FH(D1119G), a variant lacking one of the C3b-binding sites and causing atypical hemolytic uremic syndrome, we found that it detached more uniformly and easily. In further SPR experiments, KD values between FH and C3b on a custom-made chip surface were 5-fold tighter than on commercial chips and similar to those on erythrocytes. These results suggest that the chemistry at the surface on which FH acts drives conformational adjustments that are functionally critical.
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Affiliation(s)
- Elisavet Makou
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - Richard G Bailey
- EaStChem School of Chemistry, University of St. Andrews, St Andrews, Scotland KY16 9ST, United Kingdom
| | - Heather Johnston
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - John D Parkin
- EaStChem School of Chemistry, University of St. Andrews, St Andrews, Scotland KY16 9ST, United Kingdom
| | - Alison N Hulme
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom
| | - Georg Hähner
- EaStChem School of Chemistry, University of St. Andrews, St Andrews, Scotland KY16 9ST, United Kingdom
| | - Paul N Barlow
- EaStChem School of Chemistry, University of Edinburgh, Joseph Black Chemistry Building, Edinburgh, Scotland EH9 3FJ, United Kingdom .,School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3JY, United Kingdom
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11
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Schönauer R, Seidel A, Grohmann M, Lindner TH, Bergmann C, Halbritter J. Deleterious Impact of a Novel CFH Splice Site Variant in Atypical Hemolytic Uremic Syndrome. Front Genet 2019; 10:465. [PMID: 31156713 PMCID: PMC6530248 DOI: 10.3389/fgene.2019.00465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 04/30/2019] [Indexed: 12/21/2022] Open
Abstract
Atypical hemolytic uremic syndrome (aHUS) is a heterogeneous disorder characterized by microangiopathic hemolytic anemia (MAHA), thrombocytopenia, and acute kidney injury (AKI). In about 50% of cases, pathogenic variants in genes involved in the innate immune response including complement factors complement factor H (CFH), CFI, CFB, C3, and membrane co-factor protein (MCP/CD46) put patients at risk for uncontrolled activation of the alternative complement pathway. As aHUS is characterized by incomplete penetrance and presence of additional triggers for disease manifestation, genetic variant interpretation is challenging and streamlined functional variant evaluation is urgently needed. Here, we report the case of a 27-year-old female without previous medical and family history who presented with confusion, petechial bleeding, and anuric AKI. Kidney biopsy revealed glomerular thrombotic microangiopathy (TMA). Targeted next generation sequencing identified a paternally transmitted novel heterozygous splice site variant in the CFH gene [c.3134-2A>G; p.Asp1045_Thr1053del] which resulted in a partial in-frame deletion of exon 20 transcript as determined by cDNA analysis. On the protein level, the concomitant loss of 9 amino acids in the short consensus repeat (SCR) domains 17 and 18 of CFH includes a highly conserved cysteine residue, which is assumed to be essential for proper structural folding and protein function. Treatment with steroids, plasmapheresis, and the complement inhibitor eculizumab led to complete hematological and clinical remission after several months and stable renal function up to 6 years later. In conclusion, genetic investigation for pathogenic variants and evaluation of their functional impact, in particular in the case of splice site variants, is clinically relevant and enables not only better molecular understanding but helps to guide therapy with complement inhibitors.
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Affiliation(s)
- Ria Schönauer
- Division of Nephrology, University Hospital Leipzig, Leipzig, Germany
| | - Anna Seidel
- Division of Nephrology, University Hospital Leipzig, Leipzig, Germany
| | - Maik Grohmann
- Center for Human Genetics, Bioscientia, Ingelheim, Germany
| | - Tom H Lindner
- Division of Nephrology, University Hospital Leipzig, Leipzig, Germany
| | | | - Jan Halbritter
- Division of Nephrology, University Hospital Leipzig, Leipzig, Germany
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12
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Yang Y, Back CR, Gräwert MA, Wahid AA, Denton H, Kildani R, Paulin J, Wörner K, Kaiser W, Svergun DI, Sartbaeva A, Watts AG, Marchbank KJ, van den Elsen JMH. Utilization of Staphylococcal Immune Evasion Protein Sbi as a Novel Vaccine Adjuvant. Front Immunol 2019; 9:3139. [PMID: 30687332 PMCID: PMC6336717 DOI: 10.3389/fimmu.2018.03139] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 12/19/2018] [Indexed: 02/04/2023] Open
Abstract
Co-ligation of the B cell antigen receptor with complement receptor 2 on B-cells via a C3d-opsonised antigen complex significantly lowers the threshold required for B cell activation. Consequently, fusions of antigens with C3d polymers have shown great potential in vaccine design. However, these linear arrays of C3d multimers do not mimic the natural opsonisation of antigens with C3d. Here we investigate the potential of using the unique complement activating characteristics of Staphylococcal immune-evasion protein Sbi to develop a pro-vaccine approach that spontaneously coats antigens with C3 degradation products in a natural way. We show that Sbi rapidly triggers the alternative complement pathway through recruitment of complement regulators, forming tripartite complexes that act as competitive antagonists of factor H, resulting in enhanced complement consumption. These functional results are corroborated by the structure of the complement activating Sbi-III-IV:C3d:FHR-1 complex. Finally, we demonstrate that Sbi, fused with Mycobacterium tuberculosis antigen Ag85b, causes efficient opsonisation with C3 fragments, thereby enhancing the immune response significantly beyond that of Ag85b alone, providing proof of concept for our pro-vaccine approach.
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Affiliation(s)
- Yi Yang
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Catherine R Back
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Melissa A Gräwert
- Hamburg Unit, European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - Ayla A Wahid
- Department of Biology and Biochemistry, University of Bath, Bath, United Kingdom
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Rebecca Kildani
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | - Joshua Paulin
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
| | | | | | - Dmitri I Svergun
- Hamburg Unit, European Molecular Biology Laboratory, Deutsches Elektronen-Synchrotron, Hamburg, Germany
| | - Asel Sartbaeva
- Department of Chemistry, University of Bath, Bath, United Kingdom
| | - Andrew G Watts
- Department of Pharmacy and Pharmacology, University of Bath, Bath, United Kingdom
| | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University, Newcastle-upon-Tyne, United Kingdom
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13
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Wijeratne SS, Nolasco L, Li J, Jiang K, Moake JL, Kiang CH. Correlating Conformational Dynamics with the Von Willebrand Factor Reductase Activity of Factor H Using Single Molecule Force Measurements. J Phys Chem B 2018; 122:10653-10658. [PMID: 30351116 DOI: 10.1021/acs.jpcb.8b06153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Activation of proteins often involves conformational transitions, and these switches are often difficult to characterize in multidomain proteins. Full-length factor H (FH), consisting of 20 small consensus repeat domains (150 kD), is a complement control protein that regulates the activity of the alternative complement pathway. Different preparations of FH can also reduce the disulfide bonds linking large Von Willebrand factor (VWF) multimers into smaller, less adhesive forms. In contrast, commercially available purified FH (pFH) has little or no VWF reductase activity unless the pFH is chemically modified by either ethylenediaminetetraacetic acid (EDTA) or urea. We used atomic force microscopy single molecule force measurements to investigate different forms of FH, including recombinant FH and pFH, in the presence or absence of EDTA and urea, and to correlate the conformational changes to its activities. We found that the FH conformation depends on the method used for sample preparation, which affects the VWF reductase activity of FH.
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14
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Yang Y, Denton H, Davies OR, Smith-Jackson K, Kerr H, Herbert AP, Barlow PN, Pickering MC, Marchbank KJ. An Engineered Complement Factor H Construct for Treatment of C3 Glomerulopathy. J Am Soc Nephrol 2018; 29:1649-1661. [PMID: 29588430 PMCID: PMC6054357 DOI: 10.1681/asn.2017091006] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 02/26/2018] [Indexed: 01/06/2023] Open
Abstract
Background C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway of complement activation, and treatment options for C3G remain limited. Complement factor H (FH) is a potent regulator of the alternative pathway and might offer a solution, but the mass and complexity of FH makes generation of full-length FH far from trivial. We previously generated a mini-FH construct, with FH short consensus repeats 1-5 linked to repeats 18-20 (FH1-5^18-20), that was effective in experimental C3G. However, the serum t1/2 of FH1-5^18-20 was significantly shorter than that of serum-purified FH.Methods We introduced the oligomerization domain of human FH-related protein 1 (denoted by R1-2) at the carboxy or amino terminus of human FH1-5^18-20 to generate two homodimeric mini-FH constructs (FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2, respectively) in Chinese hamster ovary cells and tested these constructs using binding, fluid-phase, and erythrocyte lysis assays, followed by experiments in FH-deficient Cfh-/- mice.Results FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2 homodimerized in solution and displayed avid binding profiles on clustered C3b surfaces, particularly FHR1-2^1-5^18-20 Each construct was >10-fold more effective than FH at inhibiting cell surface complement activity in vitro and restricted glomerular basement membrane C3 deposition in vivo significantly better than FH or FH1-5^18-20 FH1-5^18-20^R1-2 had a C3 breakdown fragment binding profile similar to that of FH, a >5-fold increase in serum t1/2 compared with that of FH1-5^18-20, and significantly better retention in the kidney than FH or FH1-5^18-20Conclusions FH1-5^18-20^R1-2 may have utility as a treatment option for C3G or other complement-mediated diseases.
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Affiliation(s)
- Yi Yang
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Kate Smith-Jackson
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Heather Kerr
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Andrew P Herbert
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Paul N Barlow
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | | | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK;
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15
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Hsieh CL, Ptak CP, Tseng A, Suguiura IMDS, McDonough SP, Sritrakul T, Li T, Lin YP, Gillilan RE, Oswald RE, Chang YF. Extended low-resolution structure of a Leptospira antigen offers high bactericidal antibody accessibility amenable to vaccine design. eLife 2017; 6:e30051. [PMID: 29210669 PMCID: PMC5749957 DOI: 10.7554/elife.30051] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 12/02/2017] [Indexed: 01/16/2023] Open
Abstract
Pathogens rely on proteins embedded on their surface to perform tasks essential for host infection. These obligatory structures exposed to the host immune system provide important targets for rational vaccine design. Here, we use a systematically designed series of multi-domain constructs in combination with small angle X-ray scattering (SAXS) to determine the structure of the main immunoreactive region from a major antigen from Leptospira interrogans, LigB. An anti-LigB monoclonal antibody library exhibits cell binding and bactericidal activity with extensive domain coverage complementing the elongated architecture observed in the SAXS structure. Combining antigenic motifs in a single-domain chimeric immunoglobulin-like fold generated a vaccine that greatly enhances leptospiral protection over vaccination with single parent domains. Our study demonstrates how understanding an antigen's structure and antibody accessible surfaces can guide the design and engineering of improved recombinant antigen-based vaccines.
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Affiliation(s)
- Ching-Lin Hsieh
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Christopher P Ptak
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
- Department of Molecular Medicine, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Andrew Tseng
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | | | - Sean P McDonough
- Department of Biomedical Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Tepyuda Sritrakul
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Ting Li
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Yi-Pin Lin
- Division of Infectious DiseaseWadsworth Center, New York State Department of HealthAlbanyUnited States
| | - Richard E Gillilan
- Macromolecular Diffraction Facility at CHESS (MacCHESS)Cornell UniversityIthacaUnited States
| | - Robert E Oswald
- Department of Molecular Medicine, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Yung-Fu Chang
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary MedicineCornell UniversityIthacaUnited States
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16
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HpARI Protein Secreted by a Helminth Parasite Suppresses Interleukin-33. Immunity 2017; 47:739-751.e5. [PMID: 29045903 PMCID: PMC5655542 DOI: 10.1016/j.immuni.2017.09.015] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2016] [Revised: 06/09/2017] [Accepted: 09/25/2017] [Indexed: 12/22/2022]
Abstract
Infection by helminth parasites is associated with amelioration of allergic reactivity, but mechanistic insights into this association are lacking. Products secreted by the mouse parasite Heligmosomoides polygyrus suppress type 2 (allergic) immune responses through interference in the interleukin-33 (IL-33) pathway. Here, we identified H. polygyrus Alarmin Release Inhibitor (HpARI), an IL-33-suppressive 26-kDa protein, containing three predicted complement control protein (CCP) modules. In vivo, recombinant HpARI abrogated IL-33, group 2 innate lymphoid cell (ILC2) and eosinophilic responses to Alternaria allergen administration, and diminished eosinophilic responses to Nippostrongylus brasiliensis, increasing parasite burden. HpARI bound directly to both mouse and human IL-33 (in the cytokine’s activated state) and also to nuclear DNA via its N-terminal CCP module pair (CCP1/2), tethering active IL-33 within necrotic cells, preventing its release, and forestalling initiation of type 2 allergic responses. Thus, HpARI employs a novel molecular strategy to suppress type 2 immunity in both infection and allergy. HpARI is a suppressor of IL-33 release and consequent allergic sensitization HpARI binds active IL-33 and nuclear DNA, tethering IL-33 within necrotic cells HpARI is active against both human and murine IL-33
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17
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Harder MJ, Kuhn N, Schrezenmeier H, Höchsmann B, von Zabern I, Weinstock C, Simmet T, Ricklin D, Lambris JD, Skerra A, Anliker M, Schmidt CQ. Incomplete inhibition by eculizumab: mechanistic evidence for residual C5 activity during strong complement activation. Blood 2017; 129:970-980. [PMID: 28028023 PMCID: PMC5324716 DOI: 10.1182/blood-2016-08-732800] [Citation(s) in RCA: 103] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2016] [Accepted: 12/16/2016] [Indexed: 12/21/2022] Open
Abstract
Eculizumab inhibits the terminal, lytic pathway of complement by blocking the activation of the complement protein C5 and shows remarkable clinical benefits in certain complement-mediated diseases. However, several reports suggest that activation of C5 is not always completely suppressed in patients even under excess of eculizumab over C5, indicating that residual C5 activity may derogate the drug's therapeutic benefit under certain conditions. By using eculizumab and the tick-derived C5 inhibitor coversin, we determined conditions ex vivo in which C5 inhibition is incomplete. The degree of such residual lytic activity depended on the strength of the complement activator and the resulting surface density of the complement activation product C3b, which autoamplifies via the alternative pathway (AP) amplification loop. We show that at high C3b densities required for binding and activation of C5, both inhibitors reduce but do not abolish this interaction. The decrease of C5 binding to C3b clusters in the presence of C5 inhibitors correlated with the levels of residual hemolysis. However, by employing different C5 inhibitors simultaneously, residual hemolytic activity could be abolished. The importance of AP-produced C3b clusters for C5 activation in the presence of eculizumab was corroborated by the finding that residual hemolysis after forceful activation of the classical pathway could be reduced by blocking the AP. By providing insights into C5 activation and inhibition, our study delivers the rationale for the clinically observed phenomenon of residual terminal pathway activity under eculizumab treatment with important implications for anti-C5 therapy in general.
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Affiliation(s)
- Markus J Harder
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Nadine Kuhn
- Lehrstuhl für Biologische Chemie, Technische Universität München, Freising, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
- Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany; and
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
- Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany; and
| | - Inge von Zabern
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
- Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany; and
| | - Christof Weinstock
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
- Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany; and
| | - Thomas Simmet
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
| | - Daniel Ricklin
- Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany; and
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA
| | - Arne Skerra
- Lehrstuhl für Biologische Chemie, Technische Universität München, Freising, Germany
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, Ulm, Germany
- Institute of Clinical Transfusion Medicine and Immunogenetics Ulm, German Red Cross Blood Transfusion Service and University Hospital of Ulm, Ulm, Germany; and
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, Ulm, Germany
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Parente R, Clark SJ, Inforzato A, Day AJ. Complement factor H in host defense and immune evasion. Cell Mol Life Sci 2016; 74:1605-1624. [PMID: 27942748 PMCID: PMC5378756 DOI: 10.1007/s00018-016-2418-4] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Revised: 11/08/2016] [Accepted: 11/09/2016] [Indexed: 12/30/2022]
Abstract
Complement is the major humoral component of the innate immune system. It recognizes pathogen- and damage-associated molecular patterns, and initiates the immune response in coordination with innate and adaptive immunity. When activated, the complement system unleashes powerful cytotoxic and inflammatory mechanisms, and thus its tight control is crucial to prevent damage to host tissues and allow restoration of immune homeostasis. Factor H is the major soluble inhibitor of complement, where its binding to self markers (i.e., particular glycan structures) prevents complement activation and amplification on host surfaces. Not surprisingly, mutations and polymorphisms that affect recognition of self by factor H are associated with diseases of complement dysregulation, such as age-related macular degeneration and atypical haemolytic uremic syndrome. In addition, pathogens (i.e., non-self) and cancer cells (i.e., altered-self) can hijack factor H to evade the immune response. Here we review recent (and not so recent) literature on the structure and function of factor H, including the emerging roles of this protein in the pathophysiology of infectious diseases and cancer.
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Affiliation(s)
- Raffaella Parente
- Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, 20089, Milan, Italy
| | - Simon J Clark
- Division of Evolution and Genomic Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK
| | - Antonio Inforzato
- Humanitas Clinical and Research Center, Via Manzoni 56, Rozzano, 20089, Milan, Italy. .,Department of Medical Biotechnologies and Translational Medicine, University of Milan, Via Vanvitelli 32, 20129, Milan, Italy.
| | - Anthony J Day
- Wellcome Trust Centre for Cell-Matrix Research, Division of Cell-Matrix Biology and Regenerative Medicine, School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Oxford Road, Manchester, M13 9PT, UK.
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Mapping the Complement Factor H-Related Protein 1 (CFHR1):C3b/C3d Interactions. PLoS One 2016; 11:e0166200. [PMID: 27814381 PMCID: PMC5096715 DOI: 10.1371/journal.pone.0166200] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 10/24/2016] [Indexed: 11/19/2022] Open
Abstract
Complement factor H-related protein 1 (CFHR1) is a complement regulator which has been reported to regulate complement by blocking C5 convertase activity and interfering with C5b surface association. CFHR1 also competes with complement factor H (CFH) for binding to C3b, and may act as an antagonist of CFH-directed regulation on cell surfaces. We have employed site-directed mutagenesis in conjunction with ELISA-based and functional assays to isolate the binding interaction that CFHR1 undertakes with complement components C3b and C3d to a single shared interface. The C3b/C3d:CFHR1 interface is identical to that which occurs between the two C-terminal domains (SCR19-20) of CFH and C3b. Moreover, we have been able to corroborate that dimerization of CFHR1 is necessary for this molecule to bind effectively to C3b and C3d, or compete with CFH. Finally, we have established that CFHR1 competes with complement factor H-like protein 1 (CFHL-1) for binding to C3b. CFHL-1 is a CFH gene splice variant, which is almost identical to the N-terminal 7 domains of CFH (SCR1-7). CFHR1, therefore, not only competes with the C-terminus of CFH for binding to C3b, but also sterically blocks the interaction that the N-terminus of CFH undertakes with C3b, and which is required for CFH-regulation.
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20
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Creating functional sophistication from simple protein building blocks, exemplified by factor H and the regulators of complement activation. Biochem Soc Trans 2016; 43:812-8. [PMID: 26517887 DOI: 10.1042/bst20150074] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Complement control protein modules (CCPs) occur in numerous functionally diverse extracellular proteins. Also known as short consensus repeats (SCRs) or sushi domains each CCP contains approximately 60 amino acid residues, including four consensus cysteines participating in two disulfide bonds. Varying in length and sequence, CCPs adopt a β-sandwich type fold and have an overall prolate spheroidal shape with N- and C-termini lying close to opposite poles of the long axis. CCP-containing proteins are important as cytokine receptors and in neurotransmission, cell adhesion, blood clotting, extracellular matrix formation, haemoglobin metabolism and development, but CCPs are particularly well represented in the vertebrate complement system. For example, factor H (FH), a key soluble regulator of the alternative pathway of complement activation, is made up entirely from a chain of 20 CCPs joined by short linkers. Collectively, therefore, the 20 CCPs of FH must mediate all its functional capabilities. This is achieved via collaboration and division of labour among these modules. Structural studies have illuminated the dynamic architectures that allow FH and other CCP-rich proteins to perform their biological functions. These are largely the products of a highly varied set of intramolecular interactions between CCPs. The CCP can act as building block, spacer, highly versatile recognition site or dimerization mediator. Tandem CCPs may form composite binding sites or contribute to flexible, rigid or conformationally 'switchable' segments of the parent proteins.
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21
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Buhlmann D, Eberhardt HU, Medyukhina A, Prodinger WM, Figge MT, Zipfel PF, Skerka C. FHR3 Blocks C3d-Mediated Coactivation of Human B Cells. THE JOURNAL OF IMMUNOLOGY 2016; 197:620-9. [PMID: 27279373 DOI: 10.4049/jimmunol.1600053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Accepted: 05/05/2016] [Indexed: 01/27/2023]
Abstract
The autoimmune renal disease deficient for complement factor H-related (CFHR) genes and autoantibody-positive form of hemolytic uremic syndrome is characterized by the presence of autoantibodies specific for the central complement regulator, factor H, combined with a homozygous deficiency, mostly in CFHR3 and CFHR1 Because FHR3 and FHR1 bind to C3d and inactivated C3b, which are ligands for complement receptor type 2 (CR2/CD21), the aim of the current study was to examine whether FHR3-C3d or FHR1-C3d complexes modulate B cell activation. Laser-scanning microscopy and automated image-based analysis showed that FHR3, but not FHR1 or factor H, blocked B cell activation by the BCR coreceptor complex (CD19/CD21/CD81). FHR3 bound to C3d, thereby inhibiting the interaction between C3d and CD21 and preventing colocalization of the coreceptor complex with the BCR. FHR3 neutralized the adjuvant effect of C3d on B cells, as shown by inhibited intracellular CD19 and Akt phosphorylation in Raji cells, as well as Ca(2+) release in peripheral B cells. In cases of CFHR3/CFHR1 deficiency, the FHR3 binding sites on C3d are occupied by factor H, which lacks B cell-inhibitory functions. These data provide evidence that FHR3, which is absent in patients with the autoimmune form of hemolytic uremic syndrome, is involved in B cell regulation.
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Affiliation(s)
- Denise Buhlmann
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Hannes U Eberhardt
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Anna Medyukhina
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany
| | - Wolfgang M Prodinger
- Department of Hygiene and Medical Microbiology, Medical University of Innsbruck, A-6020 Innsbruck, Austria; and
| | - Marc Thilo Figge
- Applied Systems Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany; Friedrich Schiller University, 07743 Jena, Germany
| | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany; Friedrich Schiller University, 07743 Jena, Germany
| | - Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, 07745 Jena, Germany;
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22
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Bushey RT, Moody MA, Nicely NL, Haynes BF, Alam SM, Keir ST, Bentley RC, Roy Choudhury K, Gottlin EB, Campa MJ, Liao HX, Patz EF. A Therapeutic Antibody for Cancer, Derived from Single Human B Cells. Cell Rep 2016; 15:1505-1513. [PMID: 27160908 DOI: 10.1016/j.celrep.2016.04.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Revised: 02/17/2016] [Accepted: 04/05/2016] [Indexed: 12/21/2022] Open
Abstract
Some patients with cancer never develop metastasis, and their host response might provide cues for innovative treatment strategies. We previously reported an association between autoantibodies against complement factor H (CFH) and early-stage lung cancer. CFH prevents complement-mediated cytotoxicity (CDC) by inhibiting formation of cell-lytic membrane attack complexes on self-surfaces. In an effort to translate these findings into a biologic therapy for cancer, we isolated and expressed DNA sequences encoding high-affinity human CFH antibodies directly from single, sorted B cells obtained from patients with the antibody. The co-crystal structure of a CFH antibody-target complex shows a conformational change in the target relative to the native structure. This recombinant CFH antibody causes complement activation and release of anaphylatoxins, promotes CDC of tumor cell lines, and inhibits tumor growth in vivo. The isolation of anti-tumor antibodies derived from single human B cells represents an alternative paradigm in antibody drug discovery.
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MESH Headings
- Alanine/genetics
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/genetics
- Antibodies, Monoclonal/therapeutic use
- Autoantibodies/immunology
- B-Lymphocytes/immunology
- Cell Line, Tumor
- Cell Proliferation
- Cloning, Molecular
- Complement Factor H/chemistry
- Complement Factor H/immunology
- Complement System Proteins/immunology
- Crystallography, X-Ray
- Cytotoxicity, Immunologic
- Disease Models, Animal
- Epitopes/immunology
- Gene Rearrangement
- Humans
- Lung Neoplasms/drug therapy
- Lung Neoplasms/pathology
- Mice, Nude
- Models, Molecular
- Mutagenesis/genetics
- Peptides/chemistry
- Peptides/immunology
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Affiliation(s)
- Ryan T Bushey
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - M Anthony Moody
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Pediatrics, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA
| | - Nathan L Nicely
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Barton F Haynes
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Immunology, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | - S Munir Alam
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA
| | - Stephen T Keir
- Department of Neurosurgery, Duke University Medical Center, Durham, NC 27710, USA
| | - Rex C Bentley
- Department of Pathology, Duke University Medical Center, Durham, NC 27710, USA
| | - Kingshuk Roy Choudhury
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Biostatistics and Bioinformatics, Duke University Medical Center, Durham, NC 27710, USA
| | - Elizabeth B Gottlin
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Michael J Campa
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Hua-Xin Liao
- Duke Human Vaccine Institute, Duke University Medical Center, Durham, NC 27710, USA; Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA.
| | - Edward F Patz
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA; Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA.
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23
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Probing the solution structure of Factor H using hydroxyl radical protein footprinting and cross-linking. Biochem J 2016; 473:1805-19. [PMID: 27099340 DOI: 10.1042/bcj20160225] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 04/19/2016] [Indexed: 11/17/2022]
Abstract
The control protein Factor H (FH) is a crucial regulator of the innate immune complement system, where it is active on host cell membranes and in the fluid phase. Mutations impairing the binding capacity of FH lead to severe autoimmune diseases. Here, we studied the solution structure of full-length FH, in its free state and bound to the C3b complement protein. To do so, we used two powerful techniques, hydroxyl radical protein footprinting (HRPF) and chemical cross-linking coupled with mass spectrometry (MS), to probe the structural rearrangements and to identify protein interfaces. The footprint of C3b on the FH surface matches existing crystal structures of C3b complexed with the N- and C-terminal fragments of FH. In addition, we revealed the position of the central portion of FH in the protein complex. Moreover, cross-linking studies confirmed the involvement of the C-terminus in the dimerization of FH.
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24
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Olivar R, Luque A, Cárdenas-Brito S, Naranjo-Gómez M, Blom AM, Borràs FE, Rodriguez de Córdoba S, Zipfel PF, Aran JM. The Complement Inhibitor Factor H Generates an Anti-Inflammatory and Tolerogenic State in Monocyte-Derived Dendritic Cells. THE JOURNAL OF IMMUNOLOGY 2016; 196:4274-90. [PMID: 27076676 DOI: 10.4049/jimmunol.1500455] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Accepted: 02/27/2016] [Indexed: 12/14/2022]
Abstract
The activation of the complement system is a key initiating step in the protective innate immune-inflammatory response against injury, although it may also cause harm if left unchecked. The structurally related soluble complement inhibitors C4b-binding protein (C4BP) and factor H (FH) exert a tight regulation of the classical/lectin and alternative pathways of complement activation, respectively, attenuating the activity of the C3/C5 convertases and, consequently, avoiding serious damage to host tissues. We recently reported that the acute-phase C4BP isoform C4BP lacking the β-chain plays a pivotal role in the modulation of the adaptive immune responses. In this study, we demonstrate that FH acts in the early stages of monocyte to dendritic cell (DC) differentiation and is able to promote a distinctive tolerogenic and anti-inflammatory profile on monocyte-derived DCs (MoDCs) challenged by a proinflammatory stimulus. Accordingly, FH-treated and LPS-matured MoDCs are characterized by altered cytoarchitecture, resembling immature MoDCs, lower expression of the maturation marker CD83 and the costimulatory molecules CD40, CD80, and CD86, decreased production of key proinflammatory Th1-cytokines (IL-12, TNF-α, IFN-γ, IL-6, and IL-8), and preferential production of immunomodulatory mediators (IL-10 and TGF-β). Moreover, FH-treated MoDCs show low Ag uptake and, when challenged with LPS, display reduced CCR7 expression and chemotactic migration, impaired CD4(+) T cell alloproliferation, inhibition of IFN-γ secretion by the allostimulated T cells, and, conversely, induction of CD4(+)CD127(low/negative)CD25(high)Foxp3(+) regulatory T cells. Thus, this novel noncanonical role of FH as an immunological brake able to directly affect the function of MoDCs in an inflammatory environment may exhibit therapeutic potential in hypersensitivity, transplantation, and autoimmunity.
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Affiliation(s)
- Rut Olivar
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Ana Luque
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Sonia Cárdenas-Brito
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain
| | - Mar Naranjo-Gómez
- Innovation in Vesicles and Cells for Application Therapy Group, Germans Trias i Pujol Health Sciences Research Institute, 08916 Badalona, Barcelona, Spain; Nephrology Service, Germans Trias i Pujol University Hospital, 08916 Badalona, Barcelona, Spain
| | - Anna M Blom
- Section of Medical Protein Chemistry, Department of Laboratory Medicine, Lund University, 20502 Malmö, Sweden
| | - Francesc E Borràs
- Innovation in Vesicles and Cells for Application Therapy Group, Germans Trias i Pujol Health Sciences Research Institute, 08916 Badalona, Barcelona, Spain; Nephrology Service, Germans Trias i Pujol University Hospital, 08916 Badalona, Barcelona, Spain
| | | | - Peter F Zipfel
- Department of Infection Biology, Leibniz Institute for Natural Products Research and Infection Biology, 07745 Jena, Germany
| | - Josep M Aran
- Human Molecular Genetics Group, Bellvitge Biomedical Research Institute, L'Hospitalet de Llobregat, 08908 Barcelona, Spain;
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25
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Harder MJ, Anliker M, Höchsmann B, Simmet T, Huber-Lang M, Schrezenmeier H, Ricklin D, Lambris JD, Barlow PN, Schmidt CQ. Comparative Analysis of Novel Complement-Targeted Inhibitors, MiniFH, and the Natural Regulators Factor H and Factor H-like Protein 1 Reveal Functional Determinants of Complement Regulation. THE JOURNAL OF IMMUNOLOGY 2015; 196:866-76. [PMID: 26643478 DOI: 10.4049/jimmunol.1501919] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Accepted: 11/04/2015] [Indexed: 01/08/2023]
Abstract
The serum proteins factor H (FH), consisting of 20 complement control protein modules (CCPs), and its splice product FH-like protein 1 (FHL-1; consisting of CCPs 1-7) are major regulators of the alternative pathway (AP) of complement activation. The engineered version of FH, miniFH, contains only the N- and C-terminal portions of FH linked by an optimized peptide and shows ∼ 10-fold higher ex vivo potency. We explored the hypothesis that regulatory potency is enhanced by unmasking of a ligand-binding site in the C-terminal CCPs 19-20 that is cryptic in full-length native FH. Therefore, we produced an FH variant lacking the central domains 10-15 (FHΔ10-15). To explore how avidity affects regulatory strength, we generated a duplicated version of miniFH, termed midiFH. We compared activities of FHΔ10-15 and midiFH to miniFH, FH, and FHL-1. Relative to FH, FHΔ10-15 exhibited an altered binding profile toward C3 activation products and a 5-fold-enhanced complement regulation on a paroxysmal nocturnal hemoglobinuria patient's erythrocytes. Contrary to dogma, FHL-1 and FH exhibited equal regulatory activity, suggesting that the role of FHL-1 in AP regulation has been underestimated. Unexpectedly, a substantially increased avidity for complement opsonins, as seen in midiFH, did not potentiate the inhibitory potential on host cells. In conclusion, comparisons of engineered and native FH-based regulators have identified features that determine high AP regulatory activity on host cells. Unrestricted availability of FH CCPs 19-20 and an optimal spatial orientation between the N- and C-terminal FH regions are key.
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Affiliation(s)
- Markus J Harder
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany
| | - Markus Anliker
- Institute of Transfusion Medicine, University of Ulm, 89081 Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Service Baden-Württemberg - Hessen and University Hospital Ulm, 89081 Ulm, Germany
| | - Britta Höchsmann
- Institute of Transfusion Medicine, University of Ulm, 89081 Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Service Baden-Württemberg - Hessen and University Hospital Ulm, 89081 Ulm, Germany
| | - Thomas Simmet
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany
| | - Markus Huber-Lang
- Department of Traumatology, Center of Surgery, University of Ulm, 89081 Ulm, Germany
| | - Hubert Schrezenmeier
- Institute of Transfusion Medicine, University of Ulm, 89081 Ulm, Germany; Institute of Clinical Transfusion Medicine and Immunogenetics, German Red Cross Blood Service Baden-Württemberg - Hessen and University Hospital Ulm, 89081 Ulm, Germany
| | - Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19102
| | - Paul N Barlow
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom; and School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3JJ, United Kingdom
| | - Christoph Q Schmidt
- Institute of Pharmacology of Natural Products and Clinical Pharmacology, Ulm University, 89081 Ulm, Germany;
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26
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Merle NS, Church SE, Fremeaux-Bacchi V, Roumenina LT. Complement System Part I - Molecular Mechanisms of Activation and Regulation. Front Immunol 2015; 6:262. [PMID: 26082779 PMCID: PMC4451739 DOI: 10.3389/fimmu.2015.00262] [Citation(s) in RCA: 984] [Impact Index Per Article: 109.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Accepted: 05/11/2015] [Indexed: 12/12/2022] Open
Abstract
Complement is a complex innate immune surveillance system, playing a key role in defense against pathogens and in host homeostasis. The complement system is initiated by conformational changes in recognition molecular complexes upon sensing danger signals. The subsequent cascade of enzymatic reactions is tightly regulated to assure that complement is activated only at specific locations requiring defense against pathogens, thus avoiding host tissue damage. Here, we discuss the recent advances describing the molecular and structural basis of activation and regulation of the complement pathways and their implication on physiology and pathology. This article will review the mechanisms of activation of alternative, classical, and lectin pathways, the formation of C3 and C5 convertases, the action of anaphylatoxins, and the membrane-attack-complex. We will also discuss the importance of structure-function relationships using the example of atypical hemolytic uremic syndrome. Lastly, we will discuss the development and benefits of therapies using complement inhibitors.
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Affiliation(s)
- Nicolas S Merle
- UMR_S 1138, Cordeliers Research Center, Complement and Diseases Team, INSERM , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France
| | - Sarah Elizabeth Church
- UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France ; UMR_S 1138, Cordeliers Research Center, Integrative Cancer Immunology Team, INSERM , Paris , France
| | - Veronique Fremeaux-Bacchi
- UMR_S 1138, Cordeliers Research Center, Complement and Diseases Team, INSERM , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France ; Service d'Immunologie Biologique, Assistance Publique-Hôpitaux de Paris, Hôpital Européen Georges-Pompidou , Paris , France
| | - Lubka T Roumenina
- UMR_S 1138, Cordeliers Research Center, Complement and Diseases Team, INSERM , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Paris Cité, Université Paris Descartes , Paris , France ; UMR_S 1138, Centre de Recherche des Cordeliers, Sorbonne Universités, Université Pierre et Marie Curie-Paris , Paris , France
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27
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de Córdoba SR. Complement genetics and susceptibility to inflammatory disease. Lessons from genotype-phenotype correlations. Immunobiology 2015; 221:709-14. [PMID: 26004345 DOI: 10.1016/j.imbio.2015.05.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 05/06/2015] [Indexed: 10/23/2022]
Abstract
Different genome-wide linkage and association studies performed during the last 15 years have associated mutations and polymorphisms in complement genes with different diseases characterized by tissue damage and inflammation. These are complex disorders in which genetically susceptible individuals usually develop the pathology as a consequence of environmental triggers. Although complement dysregulation is a common feature of these pathologies, how the disease phenotype is determined is only partly understood. One way to advance understanding is to focus the research in the analysis of the peculiar genotype-phenotype correlations that characterize some of these diseases. I will review here how understanding the functional consequences of these disease-associated complement genetic variants is providing us with novel insights into the underpinning complement biology and a better knowledge of the pathogenic mechanisms underlying each of these pathologies. These advances have important therapeutic and diagnostic implications.
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28
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New functional and structural insights from updated mutational databases for complement factor H, Factor I, membrane cofactor protein and C3. Biosci Rep 2014; 34:BSR20140117. [PMID: 25188723 PMCID: PMC4206863 DOI: 10.1042/bsr20140117] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
aHUS (atypical haemolytic uraemic syndrome), AMD (age-related macular degeneration) and other diseases are associated with defective AP (alternative pathway) regulation. CFH (complement factor H), CFI (complement factor I), MCP (membrane cofactor protein) and C3 exhibited the most disease-associated genetic alterations in the AP. Our interactive structural database for these was updated with a total of 324 genetic alterations. A consensus structure for the SCR (short complement regulator) domain showed that the majority (37%) of SCR mutations occurred at its hypervariable loop and its four conserved Cys residues. Mapping 113 missense mutations onto the CFH structure showed that over half occurred in the C-terminal domains SCR-15 to -20. In particular, SCR-20 with the highest total of affected residues is associated with binding to C3d and heparin-like oligosaccharides. No clustering of 49 missense mutations in CFI was seen. In MCP, SCR-3 was the most affected by 23 missense mutations. In C3, the neighbouring thioester and MG (macroglobulin) domains exhibited most of 47 missense mutations. The mutations in the regulators CFH, CFI and MCP involve loss-of-function, whereas those for C3 involve gain-of-function. This combined update emphasizes the importance of the complement AP in inflammatory disease, clarifies the functionally important regions in these proteins, and will facilitate diagnosis and therapy. A new compilation of 324 mutations in four major proteins from the complement alternative pathway reveals mutational hotspots in factor H and complement C3, and less so in factor I and membrane cofactor protein. Their associations with function are discussed.
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29
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Nolasco L, Nolasco J, Feng S, Afshar-Kharghan V, Moake J. Human Complement Factor H Is a Reductase for Large Soluble von Willebrand Factor Multimers—Brief Report. Arterioscler Thromb Vasc Biol 2013; 33:2524-8. [DOI: 10.1161/atvbaha.113.302280] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Leticia Nolasco
- From the Department of Bioengineering, Rice University, Houston, TX (L.N., J.N., J.M.); and Department of Pulmonary Medicine, M.D. Anderson Cancer Center, Houston, TX (S.F., V.A.-K.)
| | - Jennifer Nolasco
- From the Department of Bioengineering, Rice University, Houston, TX (L.N., J.N., J.M.); and Department of Pulmonary Medicine, M.D. Anderson Cancer Center, Houston, TX (S.F., V.A.-K.)
| | - Shuju Feng
- From the Department of Bioengineering, Rice University, Houston, TX (L.N., J.N., J.M.); and Department of Pulmonary Medicine, M.D. Anderson Cancer Center, Houston, TX (S.F., V.A.-K.)
| | - Vahid Afshar-Kharghan
- From the Department of Bioengineering, Rice University, Houston, TX (L.N., J.N., J.M.); and Department of Pulmonary Medicine, M.D. Anderson Cancer Center, Houston, TX (S.F., V.A.-K.)
| | - Joel Moake
- From the Department of Bioengineering, Rice University, Houston, TX (L.N., J.N., J.M.); and Department of Pulmonary Medicine, M.D. Anderson Cancer Center, Houston, TX (S.F., V.A.-K.)
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30
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Skerka C, Chen Q, Fremeaux-Bacchi V, Roumenina LT. Complement factor H related proteins (CFHRs). Mol Immunol 2013; 56:170-80. [PMID: 23830046 DOI: 10.1016/j.molimm.2013.06.001] [Citation(s) in RCA: 178] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 05/08/2013] [Indexed: 02/06/2023]
Abstract
Factor H related proteins comprise a group of five plasma proteins: CFHR1, CFHR2, CFHR3, CFHR4 and CFHR5, and each member of this group binds to the central complement component C3b. Mutations, genetic deletions, duplications or rearrangements in the individual CFHR genes are associated with a number of diseases including atypical hemolytic uremic syndrome (aHUS), C3 glomerulopathies (C3 glomerulonephritis (C3GN), dense deposit disease (DDD) and CFHR5 nephropathy), IgA nephropathy, age related macular degeneration (AMD) and systemic lupus erythematosus (SLE). Although complement regulatory functions were attributed to most of the members of the CFHR protein family, the precise role of each CFHR protein in complement activation and the exact contribution to disease pathology is still unclear. Recent publications show that CFHR proteins form homo- as well as heterodimers. Genetic abnormalities within the CFHR gene locus can result in hybrid proteins with affected dimerization or recognition domains which cause defective functions. Here we summarize the recent data about CFHR genes and proteins in order to better understand the role of CFHR proteins in complement activation and in complement associated diseases.
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Affiliation(s)
- Christine Skerka
- Department of Infection Biology, Leibniz Institute for Natural Product Research and Infection Biology, Jena, Germany.
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31
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Abstract
Factor H (FH) is a soluble regulator of the proteolytic cascade at the core of the evolutionarily ancient vertebrate complement system. Although FH consists of a single chain of similar protein modules, it has a demanding job description. Its chief role is to prevent complement-mediated injury to healthy host cells and tissues. This entails recognition of molecular patterns on host surfaces combined with control of one of nature's most dangerous examples of a positive-feedback loop. In this way, FH modulates, where and when needed, an amplification process that otherwise exponentially escalates the production of the pro-inflammatory, pro-phagocytic, and pro-cytolytic cleavage products of complement proteins C3 and C5. Mutations and single-nucleotide polymorphisms in the FH gene and autoantibodies against FH predispose individuals to diseases, including age-related macular degeneration, dense-deposit disease, and atypical hemolytic uremic syndrome. Moreover, deletions or variations of genes for FH-related proteins also influence the risk of disease. Numerous pathogens hijack FH and use it for self-defense. As reviewed herein, a molecular understanding of FH function is emerging. While its functional oligomeric status remains uncertain, progress has been achieved in characterizing its three-dimensional architecture and, to a lesser extent, its intermodular flexibility. Models are proposed, based on the reconciliation of older data with a wealth of recent evidence, in which a latent circulating form of FH is activated by its principal target, C3b tethered to a self-surface. Such models suggest hypotheses linking sequence variations to pathophysiology, but improved, more quantitative, functional assays and rigorous data analysis are required to test these ideas.
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Affiliation(s)
- Elisavet Makou
- School of Chemistry, University of Edinburgh, Edinburgh EH9 3JJ, U.K
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32
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Blanchet CE, Svergun DI. Small-Angle X-Ray Scattering on Biological Macromolecules and Nanocomposites in Solution. Annu Rev Phys Chem 2013; 64:37-54. [DOI: 10.1146/annurev-physchem-040412-110132] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Clement E. Blanchet
- European Molecular Biology Laboratory (EMBL) Hamburg, 22603 Hamburg, Germany;
| | - Dmitri I. Svergun
- European Molecular Biology Laboratory (EMBL) Hamburg, 22603 Hamburg, Germany;
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33
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Lea SM, Johnson S. Putting the structure into complement. Immunobiology 2013; 217:1117-21. [PMID: 22964238 DOI: 10.1016/j.imbio.2012.07.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 07/13/2012] [Accepted: 07/15/2012] [Indexed: 11/25/2022]
Abstract
In a field where structure has finally begun to have a real impact, a series of new structures over the last two years have further extended our understanding of some of the critical regulatory events of the complement system. Notably, information has begun to flow from larger assemblies of components which allow insight into the often transient assemblies critical to complement regulation at the cell surface. This review will summarise the key structures determined since the last International Complement Workshop and the insights these have given us, before highlighting some questions that still require molecular frameworks to drive understanding.
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Affiliation(s)
- Susan M Lea
- Sir William Dunn School of Pathology, South Parks Road, Oxford OX1 3RE, UK.
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Makou E, Mertens HD, Maciejewski M, Soares DC, Matis I, Schmidt CQ, Herbert AP, Svergun DI, Barlow PN. Solution structure of CCP modules 10-12 illuminates functional architecture of the complement regulator, factor H. J Mol Biol 2012; 424:295-312. [PMID: 23017427 PMCID: PMC4068365 DOI: 10.1016/j.jmb.2012.09.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Revised: 09/17/2012] [Accepted: 09/18/2012] [Indexed: 01/08/2023]
Abstract
The 155-kDa plasma glycoprotein factor H (FH), which consists of 20 complement control protein (CCP) modules, protects self-tissue but not foreign organisms from damage by the complement cascade. Protection is achieved by selective engagement of FH, via CCPs 1-4, CCPs 6-8 and CCPs 19-20, with polyanion-rich host surfaces that bear covalently attached, activation-specific, fragments of complement component C3. The role of intervening CCPs 9-18 in this process is obscured by lack of structural knowledge. We have concatenated new high-resolution solution structures of overlapping recombinant CCP pairs, 10-11 and 11-12, to form a three-dimensional structure of CCPs 10-12 and validated it by small-angle X-ray scattering of the recombinant triple-module fragment. Superimposing CCP 12 of this 10-12 structure with CCP 12 from the previously solved CCP 12-13 structure yielded an S-shaped structure for CCPs 10-13 in which modules are tilted by 80-110° with respect to immediate neighbors, but the bend between CCPs 10 and 11 is counter to the arc traced by CCPs 11-13. Including this four-CCP structure in interpretation of scattering data for the longer recombinant segments, CCPs 10-15 and 8-15, implied flexible attachment of CCPs 8 and 9 to CCP 10 but compact and intimate arrangements of CCP 14 with CCPs 12, 13 and 15. Taken together with difficulties in recombinant production of module pairs 13-14 and 14-15, the aberrant structure of CCP 13 and the variability of 13-14 linker sequences among orthologues, a structural dependency of CCP 14 on its neighbors is suggested; this has implications for the FH mechanism.
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Key Words
- ccp, complement control protein
- cr1, complement receptor type 1
- daf, decay accelerating factor
- fh, factor h
- eom, ensemble optimization method
- hsqc, heteronuclear single quantum coherence
- mcp, membrane cofactor protein
- noe, nuclear overhauser enhancement
- saxs, small-angle x-ray scattering
- tocsy, total correlated spectroscopy
- protein nmr
- protein domains
- complement system
- small-angle x-ray scattering
- regulators of complement activation
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Affiliation(s)
- Elisavet Makou
- Schools of Chemistry and Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
| | - Haydyn D.T. Mertens
- European Molecular Biology Laboratory Hamburg Outstation, c/o Deutsches Elektronen‐Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Mateusz Maciejewski
- Schools of Chemistry and Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
| | - Dinesh C. Soares
- Medical Genetics Section, Molecular Medicine Centre, Institute of Genetics and Molecular Medicine, University of Edinburgh Western General Hospital, Crewe Road South, Edinburgh EH4 2XU, UK
| | - Ilias Matis
- Schools of Chemistry and Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
| | - Christoph Q. Schmidt
- Schools of Chemistry and Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
| | - Andrew P. Herbert
- Schools of Chemistry and Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
| | - Dmitri I. Svergun
- European Molecular Biology Laboratory Hamburg Outstation, c/o Deutsches Elektronen‐Synchrotron, Notkestrasse 85, 22603 Hamburg, Germany
| | - Paul N. Barlow
- Schools of Chemistry and Biological Sciences, University of Edinburgh, West Mains Road, Edinburgh EH9 3JJ, UK
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